32 RN window run channels

[Sneezerap]

The door window run channels in my 32 RN are in need of replacement. They are currently loose and will move up and down as the window is lowered and raised.  I will be ordering new. Current length is 18 inches and they barely extend below the door latch. The window gets cocked in the opening due lack of guide when fully lowered./ I would like to extend them down another 6 inches.  Now when the run channel is longer, I wonder if I can remove and reinstall the glass?   THOUGHTS please.

[Robert Leigh]

I presume you will be installing the glass from the top so longer channels will not present a problem. I suspect that aprevious owner has shortened the channels; perhaps they had split in the lower portion where the movement takes place.